When a subject speaks, vibrations from the subject's vocal cords induce vibrations in the bones of the subject's head. A bone conduction microphone records sounds as the user speaks based on vibrations detected by, for example, sensor(s) (e.g., vibration transducer(s) such as accelerometer(s)) coupled to the subject's scalp, jaw, cheeks, etc. In a bone conduction microphone, the transducer(s) convert the mechanical vibrations from the corresponding bones (e.g., cheekbones, jawbones) into electrical signals representative of the user's speech.
Bone conduction can also be used to transmit sound to the subject. Electrical signals can be converted into vibrations that are transferred to the bones of the subject's skull. The vibrations are transmitted to the subject's inner ear, thereby conveying sound to the subject while bypassing the subject's eardrum.
The figures are not to scale. Wherever possible, the same reference numbers will be used throughout the drawing(s) and accompanying written description to refer to the same or like parts.